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What is blood for kids
Blood is present inside all of us and it is present in huge quantities. Although blood may look just like a red liquid, it contains a lot of stuff in it and all of those things together make up the fluid we call blood. Plasma makes up about half of our blood volume and it is mostly water. Plasma also consists of proteins, sugar, salts, hormones, broken down food, antibodies and waste thrown out by cells. It is this plasma that allows blood to move and get to the cells throughout the body to provide them with what they need. The plasma proteins help in stopping the blood from flowing out once we are cut and the process is known as blood clotting. There are mainly two types of cells in blood, red blood cells and white blood cells, both of which stay suspended in the plasma. The red blood cells are found in a larger number inside us and their primary function is to dissolve the inhaled oxygen into blood which allows our cells to breathe and also to carry the exhaled carbon dioxide from the cells for elimination from the body. There is basically just one type of red blood cell and they are called erythrocytes. White blood cells are the soldiers in our blood that protect us against germs and infections that are constantly trying to attack our health. White blood cells are also called leukocytes and there are many types of leukocytes like Neutrophil, Eosinophil, Basophil, Lymphocyte and Monocyte. Blood is manufactured inside the bone marrow of our vertebral column, but when we are younger, blood is made in other bones inside our body too, along with the vertebral column. To be properly circulated, blood needs a pump and our heart acts as that pump which sends it flowing through the veins and capillaries we have in all parts of the body to carry out its function.
Subscribe to the comments for this postWhat is blood agar
Blood agar is a medium for bacterial growth made from a combination of nutritious items including blood cells. Usually, the blood is from a sheep or a horse and composes five percent of the entire compound, while the gelatinous “agar” in the compound comes from the cells of the agarophyte red algae, which is commonly used for culinary or laxative purposes. It is used to observe hemolysis. Although a blood agar compound will soon have many microbes thriving in it, the main objective of preparing the blood agar is to notice whether the whole blood cells are being broken down by hemolysins and if so, which microbes are responsible. There are three types of observations in hemolysis within a blood agar Petri dish and they are as follows:
1. Alpha hemolysis – Represented by the Greek letter “α”, during alpha hemolysis, the blood cells around the colony turns greenish. The blood cells affected are broken down fractionally during alpha hemolysis.
2. Beta hemolysis – As the name suggests, it is represented by the Greek “β” and in this process entire red blood cells are broken down by the hemolysins through a process called lysis. Since the blood cells are completely broken down, therefore the area near the particular colony appears clear.
3. Gamma Hemolysis – Bacteria and microbes that do not participate in the breaking of red blood cells, neither partially or entirely, exhibit gamma hemolysis (γ).
Blood agar is not a selective medium as it is made suitable for a wide range of microbes to grow in it to simulate an ideal environment adequate for the detection of pathogenic bacteria and non-pathogenic bacteria. The environment inside a blood agar plate is not selectively manipulated to make it suitable for any particular type of bacteria or other micro organisms, which makes it a non-selective medium for growing microbes.
What is blood agglutination
The literal meaning of the term agglutination is “to glue to” and it originated from the Latin word “agglutino”. In the presence of antibodies called hemagglutinins, red blood cells come together to form a cluster, which is also joined by the antibody along with a host of other particles within the body to form an intricate compound. This whole process is known as blood agglutination or hemagglutination. If however, white blood cells clump together in the presence of an antigen instead of the red blood cells, it is called leukoagglutination. When antibodies are found in close proximity to the cells of a particular area of the body, allergic reactions are triggered off as the cells in the area come close together to prevent the antibody from gaining entry inside them. Therefore an allergic reaction is also a type of agglutination within the body.
Before transferring blood from a donor to someone who needs it, medical authorities check by cross-matching to find out whether the blood of the donor is compatible with the blood of the patient. In this process of cross-matching, the plasma from the patient and RBCs from the donor are incubated together to see whether the RBCs are showing signs of agglutination or not. If the result is positive then the donor blood is discarded as being unfit to be given to the particular patient.
Certain bacteria also react to certain antigens in the same way that the red blood cells react and clump together. Although this is not blood agglutination, it is also another form of agglutination that occurs and is similar in nature to hemagglutination. This process is used as a diagnostic tool to identify both the type of the bacteria and its antigen today, but it was first put to use by Fernand Widal by developing a test for typhoid, based on the principles of bacterial agglutination.
Stem Cell Regulations
The debate behind the ethical utilization and development of stem cell techniques and treatments has long gone on in many countries, with many governments establishing strict guidelines relating to the harvesting and exploration of stem cell treatments in many aspects. In 2001 in the United States, for instance, most exploration into totipotent and pluripotent stem cells was initially banned due to the reliance on that time of utilizing embryo cells for developing viable lines, however in 2007 a presidential order was issued allowing for the expansion of stem cell therapies and the harvesting of pluripotent stem cells to be overseen by the Secretary of Health and Human Services that would not endanger a developing human embryo in any way.
These regulations have prevented many researchers from exploring many different techniques that may endanger human life though at the same time have also allowed for further focus on the development of adult stem cell lines that can be harvested directly from mature adults and used for various medical purposes.
From a global perspective regulations are not universal, however, and some countries have been able to explore various approaches utilizing both pluripotent and totipotent stem cells derived from developing human embryos in a number of ways. China, for instance, has allowed for a more flexible approach to stem cell research, and as a result has developed a number of nerve growth techniques that have been used to successfully treat a number of patients suffering nerve damage in the past few years.
The danger with many of these techniques being explored and developed in various countries around the world lies in the actual ability for many of these derived treatments to be carried over from country to country. Any treatment developed in a country with more lax regulations, for instance, may actually be outlawed in other countries with stricter medical practices preventing any exploitation of methods that may endanger developing human fetal development.
It is anticipated that, in the coming years, as new techniques for harvesting and establishing viable stem cell lines are discovered regulations may become more lax in many ways, however at the same time many people may be afraid to explore some techniques on an ethical basis that may rely upon developing human embryos in any way for viability. While at this time a number of harvesting methods do exist that can extract viable stem cells from both developing gametes and more differentiated bodies at various stages many people are concerned as well about the long-term implications these harvesting techniques may have on human development given the relative newness of these techniques and limited ability to study the long-term effects these may have upon the bodies of both developing human beings as well as patients receiving treatment.
Amniotic stem cells
Amniotic fluid works on a number of levels to both protect and nourish developing embryos, though at the same time they also pose great potential in terms of stem cell line developments thanks to the fluid containing multipotent stem cells that can differentiate into a number of different specialized structures. As multipotent cells they have nearly the same flexibility in development capabilities as totipotent or omnipotent embryonic stem cells, however unlike embryonic stem cells amniotic stem cells can be harvested with no risk to a developing fetus – bypassing the ethical debate that has prevented many developments into highly flexible stem cell lines in the past.
The primary benefits of amniotic stem cells is that they have the potential to both expand and grow extensively with little feeder input (necessary to culture many other stem cell lines into mature, usable formats) and they are non tumorogenic, meaning that they are not prone to the potential other stem cells have of developing dangerous tumors if their growth is left unchecked over time. Additionally they intrinsically have the capabilities of differentiating into a number of specialized lines including osteogenic, adipogenic, endothelial, myogenic, neuronal and hepatic structures, effectively providing a viable solution base for many treatments down the line that are reliant upon flexible stem cell line developments.
For many communities around the world amniotic stem cells have been hailed as the “future of medicine”, with even the Vatican’s official newspaper the “Osservatore Romano” describing them as such due to their flexibility and potential for usage in a large number of medical fields without posing any risks to developing fetuses. Anmiotic stem cell banks are also being developed around the world at this time due to this high social acceptance rate, with the first ever amniotic stem cell bank being opened for both donors as well as personal storage and usage in the United States in Medford, MA a short time ago. This cell bank is open to all to contribute to and works with many universities and research institutes around the world in order to work towards future development goals.
Currently the actual application of amniotic stem cells to standard real-life situations is limited due to the relatively new nature of their research, however their status as a highly ethical way to collect and develop genetic building blocks for medical treatment means that their development is both quick and highly anticipated by both doctors and patients around the world.
Therapeutic Cloning
The basis for therapeutic cloning in terms of stem cell developments can be found in the concepts leading to the cloning of an entire organism (with many animals currently being cloned and studied as part of research into this particular method). Following the same principles, therapeutic cloning involves the removal of the central nucleus of a target cell and the depositing of the harvested DNA into an empty “receptor” stem cell that has had its own base nucleus removed for processing. Once the target DNA is inserted the cell then works to replicate and diversify based upon the inserted genetic instructions, creating new tissues or systems as necessary (and in many cases entire organisms, as first demonstrated by “Dolly” the sheep).
Therapeutic cloning, while following the same principles, focuses on replicating specific tissues or organs rather than entre cellular systems. Known also as somatic cell nuclear transfer (SCNT), therapeutic cloning has been the focus of many researchers around the world for a number of years due to the high potential it has for benefitting the medical industry as a viable source of effective tissues for those in need. This is particularly highlighted by the fact that any therapeutically cloned tissues would actually be significantly more viable in terms of being accepted by a recipient as the tissues themselves can contain the same genetic structures as the recipient and therefore be physically accepted with little impact upon the patient’s body as a whole.
For an example of how therapeutic cloning can benefit the medical industry consider a patient who is currently dying of heart, lung or liver failure. The only way to allow the individual to live (or at least live without the aid of machines) would be to somehow obtain an organ from a donor, however with waiting lists extremely long and compatibility issues a major concern (especially for people with rare blood types such as AB negative) this is not always an effective option and many people die each day because of this. Therapeutic cloning, on the other hand, would allow for specific targeted organs to be replicated for patients and implanted into their bodies as needed to replace damaged or dying cells.
Unfortunately the therapeutic cloning process for many partial clones is still being developed and is currently not viable to widespread medical application researchers anticipate that in the coming few years they will be able to successfully target specific organs for replication and effectively treat a number of diseases.
Stem Cell Lineage
Stem cells form the basis behind which the human body and the bodies of other living organisms successfully develop and maintain themselves over years. Imbued with the natural potential to replicate and “stem” into any other tissue (a process of genetic differentiation that gives them their name), stem cells must regularly go through two separate processes on a regular basis in order to maintain functionality: symmetric replication and asymmetric replication.
Symmetric replication is a process where a single stem cell divides into two identical daughter cells, each containing the initial stem cell ability to replicate additional stem cells. This allows for stem cells to regularly grow and replace dead or damaged cells without lessening their numbers, closing off systems that would otherwise be compromised without their presence.
Asymmetric replication, on the other hand, creates what is known as a progenitor cell in addition to a standard stem cell. Progenitor cells unlike stem cells can only replicate a certain number of times before being forced to permanently differentiate into a specific cell structure and become part of a set body system. This process both works to limit stem cell population growth as well as allow for the stem cells to assist other structures as necessary – their primary role in maintaining body functionality through ensured system sustainability.
Currently there are two primary theories as to why stem cells go through symmetric division at one point and asymmetric at another. One theory is that the protein receptors found within the cell membrane of each daughter cell determine at any given time whether or not the cell will be a symmetric or asymmetric offspring, adjusting based upon specific codes within the original stem cell that may be received through the body’s natural messaging processes.
A second theory, on the other hand, states that stem cells replicate either symmetrically or asymmetrically based upon environmental factors that surround them at any given time. While in a set environment, for instance, they retain symmetric division, however as new elements are introduced into their environment the cells react accordingly and differentiate to meet their specific needs. Studies have shown this to be an active factor in cell division within some organic structures, however the lack of applicability to all systems (at least the proven lack at this time) means that this is still but a theory and not a proven scientific principal as of yet.
iPSCs Retain Genetic Memory
A study of induced pluripotent stem cells (iPSCs) where cells harvested from differentiated adult cell lines and forced to be converted into highly adaptive states (similar to that of totipotent embryonic stem cells) has found that these cells retain a portion of their previous genetic code even after being cultured to grow towards a specific cell structure. This effectively means that while scientists can develop multi-functional cells from adult differentiated cell lines that they may not be able to do so effectively in a short span of time after harvesting the cells, posting new problems and benefits at the same time to stem cell research developers.
On a positive note the partially retaining stem cells can be a boon in many areas. Retaining portions of their previously encoded DNA, these cells may more easily be adapted to fit specific purposes similar to those they originate from, meaning easier conversion from a donor to a host needing support in a specific cell structure should this be necessary. Additionally the genetic memory means that progressive structures will maintain slightly different codes from targeted formats meaning that some genetic diversity can be generated even in scientifically cloned organisms, such as that which has been observed in laboratory mice created from the same host DNA.
On the downside this reminiscent code present in harvested cells means that additional work must be done in order to develop cell lines into targeted structures to match specific needs. Should a harvested cell be modified to develop into brain, nerve or other tissue cells within the same body but not fully differentiate towards the targeted structure, for instance, any treatment that is developed but still partially coded for another cell line may fail in terms of treatment and cause additional problems for a patient – even if the treatment is not rejected outright from the body.
Thankfully for many patients and researchers alike the genetic memory found in iPSCs has also been noted to progressively becoming less and less prominent through subsequent divisions of a harvested cell culture. This means that regularly culturing the same iPSC strand through successive generations can reduce the overall impact the genetic memory will have, with the memory disappearing entirely from cell lines at approximately the 16th division. While this does unfortunately mean that some treatments relying upon iPSCs may take some time for the cultures to develop fully enough to the point where they can be used to treat patients at the same time this does not mean that iPSCs are ruled out entirely as an option.
How embryonic stem cell lines are made
Embryonic stem cells are a highly sought after form of stem cell with the capability to be used in a number of different medical processes (though unfortunately they also carry with them a hefty ethical debate that prevents them from being widely studied and used at this time as well). The reason for the highly effectiveness of embryonic stem cells lies in the fact that they have not differentiated into any particular tissue or function as of yet and therefore are totipotent (also known as omnipotent), or otherwise capable of becoming virtually any biological structure they are encouraged to develop into.
In order to allow this differentiation into desired structures to occur embryonic stem cells must first be harvested from a developing blastocyst, or newly forming embryonic cell structure that forms approximately one week after a sperm successfully fertilizes an egg. These are removed from the center of the blastocyst and deposited into a growth tray for nurturing and culturing into a desired cell structure. Until the culture material is adjusted to encourage growth of a particular cell, however, the harvested cells will continue to grow and under ideal conditions will do so indefinitely so long as they never differentiate into a specific cell structure – such is the nature of stem cells as their basic function is to replicate in order to allow for other cell structures to form and differentiate into more durable structures that our body needs to function (such as tissue, nerve and bone cells).
Once the desired cell structure has been chosen for the cells to form into the nutrient content and growth conditions of the culture dish are altered in order to encourage growth to a particular cellular structure. Sometimes this can also involve the direct modification of the cell’s DNA to create a dedicated cellular structure base upon a set DNA strand (such as brain tissue or blood vessels) to specify a growth structure. By doing this the embryonic cells can be forced to differentiate into any number of cellular forms necessary for a body to function and be applied medically to treat a number of ailments, in particular any tissues or systems that may have been damaged due to trauma or other cellular disorder that damages cells and renders them unable to repair themselves (such as the case with nerve damage due to the highly differentiated nature of nerve cells and their inability to actively repair themselves like skin or other tissue cells).
Stem Cells Neurological Degeneration
Paralysis and other neurological conditions throughout the body can develop as the result of any number of conditions ranging from trauma to certain degenerative neurological conditions and can affect any number of areas ranging from the entire body to specific regions (such as the left or right half) or even simply specific appendages (such as fingers, toes, etc.). These conditions can be highly debilitating for many people and, up until recent years, if they were developed sometime in their life little could possibly be done to assist the person in regards to restoring lost functionality.
Because of the limited number of treatment options and the body’s natural difficulty in repairing damaged nerve cells paralysis has been a particularly strong focus for stem cell research over the years, especially following the successful treatment of a number of patients with nerve damage using “re-grown” cell structures cultured from stem cells in Shanghai, China. While results have been varied depending on the particular cause of the paralysis in the patient stem cell treatments have proven particularly effective in handling cases dealing with trauma, especially when allowed to be administered shortly after the trauma has been received.
Tests in Texas have proven that utilizing a modified version of adult stem cells harvested from a patient’s thigh bone marrow and specialized to target and regenerate damaged brain tissue have been able to return virtually all function that would be lost otherwise. Using this as a basis researchers have then turned to preemptive treatments of many developing neurological diseases, utilizing stem cells in the hopes of preventing conditions such as Parkinson’s, Alzheimer’s, Multiple Sclerosis and any number of other conditions affecting otherwise vulnerable brain tissue.
Currently no effective stem cell treatment is available for any chronically developing diseases that can be considered reliable for regular clinical usage, however with each passing year new developments are emerging that when coupled with other medicines and treatment methods are coming closer and closer to an effective long term solution. As for now the difficult nature presented by cases where neurological degeneration is not caused by trauma are proving particularly challenging to bypass due to the fact that any neurological regeneration instigated by stem cells will merely work to abate certain symptoms of development and will not, in fact, address the base line problem that is affecting the patient in the first place until further studies can be done that will allow doctors to target the cause in particular.